The invention relates to a light-scattering element comprising a liquid-crystalline material which is dispersed in a matrix of a transparent polymer material.
The invention also relates to an application of such a light-scattering element and to a method of manufacturing such a light-scattering element.
Light-scattering elements can suitably be used as optical components for various applications, for example in a display device.
In U.S. Pat. No. 4,688,900, a light-scattering element is described which consists of a liquid crystal material which is dispersed in a transparent polymer material in the form of drops, according to the examples in an optically isotropic thermoplastic material. In the ordinary state the element is opaque. If the temperature is increased so much that the liquid-crystal material becomes isotropic, or if an electric field is applied, the element becomes transparent. Thus, the light-scattering element can be switched between a light-transmitting and a light-scattering mode. By applying a mechanical force or an electric or magnetic field, it becomes possible to orient the liquid-crystal material so that a switchable polarizer is obtained which can be used in cooperation with a second polarizer as a light-switching element.
A disadvantage of the known element is that it cannot be used for light scattering or as a polarizer at relatively high temperatures. Besides, if said element is to be used as a polarizer it is necessary to apply a mechanical force or an electric or magnetic field as a result of which a needlessly complicated optical component is formed if the switching function is not desired.